Thinly slice the red onion and place in a bowl with lemon juice, lemon zest, and kosher salt. Toss gently and let sit for 10 minutes.

Rinse the butter beans and chickpeas, drain. Halve the artichoke hearts and chop fresh herbs. Combine all in the bowl with the onions.

In a small pan, heat olive oil and add minced garlic. Cook until golden brown, about 1-2 minutes. Stir in za'atar, sumac, and salt.

Pour the warm marinade over the salad mixture and toss gently. Let marinate at room temperature for at least 2 hours.

Serve the salad chilled or at room temperature, alongside toasted sourdough or in pita wraps.